Printer units have traditionally been employed to interface with one or more associated computers to generate images based upon control data transmitted from the associated computers. The image quality and speed of image generation can vary considerably from printer unit to printer unit and is greatly dependant upon the type of printer unit employed. Generally speaking, the high speed printer units producing high resolution images at full colour are more expensive than printer units that produce single colour, black and white images at lower speeds. In this regard, the type of printer unit employed in a particular situation is generally selected upon consideration of the type of print images to be undertaken by the printer as well as the cost of the particular printer unit.
More recently, the roles of traditional printer units have been expanded to provide additional functions, particularly in an office environment. For example, many office printer units have been developed to provide conventional printing functions as well as providing functions normally associated with copier machines. In this regard, an image reading unit such as a document scanner is coupled with the printer unit to provide a printer unit with typical copy functions. Such multi-functional units have become popular due to the fact that they can achieve tasks that were previously performed by two or more separate units, thereby reducing the costs associated with maintaining two or more separate units and reducing the amount of space required to accommodate such units.
Unfortunately, such multifunctional units are typically rather dedicated units, and are generally targeted towards office use and as such are of a size and modularity that is rather restricted. Such units are also typically expensive, in terms of conventional printer units, and as such in order for such units to compete within the printer market, the printing units and/or the image reading units employed are generally of a lesser standard then competitively priced single units. Such a trade-off can typically result in a multifunctional unit operating at inferior printing speeds and print qualities. Further to this, typical multi-functional units do not readily provide a means for the various parts of the system to be mountable to each other to enable the individual parts of the multi-functional units to be separated or added onto. In this regard, due to the lack of modularity in the design of such multi-functional units it is not possible to purchase the printer unit and the image reading unit separately, such that a printer unit can be readily transformed into a multi-functional unit upon mounting the printer unit to an image reading unit.